JP2007121039A - Inspection method of internal diameter of through hole, and nut inspection device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To inspect accurately and simply the inner diameter of a threaded hole of a nut. <P>SOLUTION: The nut N is vibrated, and the threaded hole of the vibrating nut N is irradiated with laser slit light L, and the inner diameter of the threaded hole is inspected based on a peak value of the quantity of the laser slit light L passing the threaded hole. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for inspecting an inner diameter of a through hole and a nut inspection device using the inspection method.

  The inspection of the inner diameter of the screw hole of the nut is generally performed by inserting a plug gauge into the screw hole and checking whether the plug gauge passes through the screw hole. There are two types of plug gauges: a street-side plug gauge whose outer diameter is equal to the minimum allowable dimension of the inner diameter of the screw hole, and a stationary-side plug gauge whose outer diameter is equal to the maximum allowable dimension of the inner diameter of the screw hole. The condition for a good nut is that it passes through and the plug gauge on the stop side does not pass through.

  However, the work of inserting two types of plug gauges into the screw holes of nuts produced in large quantities requires a lot of labor and labor. Therefore, the inspection of the screw hole of the nut is often performed by sampling inspection. On the other hand, nuts used for automobile parts require particularly high reliability, and if a defective product is mixed, there is a risk of serious accidents. Therefore, a nut inspection device that can easily and accurately determine the quality of the inner diameter of the screw hole of the nut has been desired.

  The problem to be solved by the present invention is to easily and accurately inspect the inner diameter of the screw hole of the nut.

  In order to solve the above-mentioned problem, based on the peak value of the light quantity of the laser beam that gives vibration to the workpiece in which the through-hole is formed, irradiates the through-hole of the vibrating workpiece with laser light, and passes through the through-hole. The inspection method of the inner diameter of the through hole for inspecting the inner diameter of the through hole was adopted for the inspection of the inner diameter of the screw hole of the nut.

  As a nut inspection device using this inspection method, for example, it has a support member for placing a nut and a vibration device for applying vibration to the support member, and a slit is formed at the position of the nut of the support member. A projector that irradiates laser light toward the light source, a light receiver that detects the laser light that has passed through the slit, and whether the screw hole diameter of the nut is good or bad based on the peak value of the light amount of the laser light detected by the light receiver It is possible to employ a nut inspection device having a configuration in which a determination unit is provided.

  In this nut inspection device, the support member is arranged to be inclined with respect to the horizontal direction, the nut on the support member is moved by vibration applied by the vibration device, and the slit is provided at a position where the moving nut passes. Preferably, the slit is formed, and more preferably, the slit is formed obliquely with respect to the moving direction of the nut.

  In the method for inspecting the inner diameter of the through hole of the present invention, the shaft of the through hole is vibrated by vibrating the workpiece, and the inner diameter of the through hole is inspected based on the peak value of the amount of laser light that has passed through the through hole. The inner diameter of the through hole can be inspected in a state where the axis of the through hole and the optical axis of the laser beam are more parallel. Therefore, even when the direction of the through hole varies depending on the workpiece, the inner diameter of the through hole can be easily and accurately inspected.

  Further, a support member for placing the nut, and a vibration device that applies vibration to the support member, forming a slit at the position of the nut of the support member, and a projector that emits laser light toward the slit, A nut inspection apparatus provided with a light receiver that detects the laser light that has passed through the slit, and a determination unit that determines the quality of the screw hole diameter of the nut based on the peak value of the light amount of the laser light detected by the light receiver. The support member vibrates the nut to swing the shaft of the screw hole and inspects the inner diameter of the screw hole based on the peak value of the amount of laser light that has passed through the screw hole. The inner diameter of the screw hole can be inspected with the optical axis being more parallel. Therefore, even when the direction of the screw hole of the nut placed on the support member varies, the inner diameter of the screw hole can be easily and accurately inspected.

  Further, the support member is arranged to be inclined with respect to the horizontal direction, the nut on the support member is moved by vibration given by the vibration device, and the slit is formed at a position through which the moving nut passes. Since the inspection is performed while moving the nut, it also has a function as a nut conveying device.

  Further, when the slit is formed obliquely with respect to the moving direction of the nut, the nut moving on the support member is not easily caught by the slit, and the nut moves more smoothly.

  FIG. 1 shows an embodiment of a nut inspection device of the present invention. This nut inspection apparatus includes a support table 1 on which a nut is placed, a projector 2 that emits laser slit light L, a light receiver 3 that detects laser slit light L emitted from the light projector 2, and a laser that is detected by the light receiver 3. And a determination unit 4 that determines whether the inner diameter of the screw hole of the nut N is good or bad based on the light amount of the slit light L.

  The support table 1 is arranged so as to be inclined with respect to the horizontal direction, and is given vibration by a vibration device (not shown), and the nut N on the support table 1 is moved by the vibration. As shown in FIG. 2, the support table 1 includes a base plate 6 in which slits 5 are formed and a pair of guide plates 7 and 7 attached to the base plate 6. As shown in FIG. 3, the guide plate 7 guides the parallel surfaces of the hexagonal portion where the wrench of the nut N is applied, and keeps the posture of the nut N constant.

  The base plate 6 is formed with a notch 8 at a position where the nut N passes, and a fixing plate 9 is inserted into the notch 8. The fixed plate 9 is fixed to a frame (not shown) independent from the vibration device, and is not directly subjected to vibration by the vibration device. Therefore, the nut N on the fixed plate 9 moves more slowly than the nut N downstream of the fixed plate 9, and a gap is formed between the nuts N downstream of the fixed plate 9.

  As shown in FIG. 1, the projector 2 irradiates the laser slit light L toward the slit 5, and the light receiver 3 detects the laser slit light L that has passed through the slit 5. Therefore, when the nut N passes through the position of the slit 5, the light quantity of the laser slit light L detected by the light receiver 3 changes. Further, the slit 5 is formed obliquely with respect to the moving direction of the nut N as shown in FIG. 3, and the nut N moving on the base plate 6 is not easily caught by the slit 5.

  The determination unit 4 calculates the peak value of the amount of light detected by the light receiver 3 when the nut N passes the position of the slit 5. Here, the amount of light detected by the light receiver 3 is as shown in FIG. 4B than when the axis n of the screw hole is inclined with respect to the optical axis of the laser slit light L as shown in FIG. As shown, the axis n of the screw hole is larger when it is parallel to the optical axis of the laser slit light L. Therefore, when the light quantity of the laser slit light L that has passed through the screw hole of the vibrating nut N takes a peak value, the screw hole axis n and the optical axis of the laser slit light L are more nearly parallel.

  Next, the determination unit 4 determines whether or not the calculated peak value is in a range corresponding to the inner diameter of the threaded hole of the non-defective nut N. If the peak value is below the range corresponding to the inner diameter of the threaded hole of the non-defective nut, it is considered that the inner diameter of the threaded hole is smaller than that of the non-defective product. Similarly, when the peak value exceeds the range corresponding to the inner diameter of the threaded hole of the non-defective nut N, it is considered that the inner diameter of the threaded hole is larger than that of the non-defective product. .

  In this nut inspection apparatus, the support table 1 vibrates the nut N to swing the shaft n of the screw hole, and inspects the inner diameter of the screw hole based on the peak value of the light quantity of the laser slit light L that has passed through the screw hole. Therefore, the inner diameter of the screw hole can be inspected in a state where the axis n of the screw hole and the optical axis of the laser slit light L are nearly parallel. Therefore, when the nut N is placed on the support table 1 with the seat surface facing upward, the inner diameter of the screw hole is accurately inspected even when the direction of the screw hole of the nut N placed on the support table 1 varies. can do.

  Moreover, since this nut inspection apparatus inspects while moving the nut N, it also has a function as a conveying apparatus for the nut N. Furthermore, since the slit 5 is formed obliquely with respect to the moving direction of the nut N, the nut N moving on the support table 1 is not easily caught by the slit 5, and the movement of the nut N is smoother.

The perspective view which shows embodiment of the nut test | inspection apparatus of this invention The disassembled perspective view of the support table of the nut test | inspection apparatus of FIG. The top view which shows the state of the movement of the nut by the nut test | inspection apparatus of FIG. (A) is a view showing a state in which the axis of the screw hole of the nut is inclined with respect to the optical axis of the laser slit light, and (b) is a state in which the axis of the screw hole of the nut is parallel to the optical axis of the laser slit light. Figure

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Support table 2 Light projector 3 Light receiver 4 Judgment part 5 Slit N Nut L Laser slit light

Claims (4)

  The workpiece N in which the through hole is formed is vibrated, the laser beam L is irradiated to the through hole of the vibrating workpiece N, and the inner diameter of the through hole is based on the peak value of the light amount of the laser beam L that has passed through the through hole. A method for inspecting the inner diameter of a through hole.   A support member 1 on which the nut N is placed and a vibration device that applies vibration to the support member 1 are formed. A slit 5 is formed at the position of the nut N of the support member 1, and the laser beam L is directed toward the slit 5. , A light receiver 3 that detects the laser light L that has passed through the slit 5, and a screw hole diameter of the nut N based on the peak value of the light quantity of the laser light L detected by the light receiver 3. The nut inspection apparatus provided with the determination part 4 which determines.   The support member 1 is arranged to be inclined with respect to the horizontal direction, the nut N on the support member 1 is moved by vibration applied by the vibration device, and the slit 5 is formed at a position where the moving nut N passes. The nut inspection apparatus according to claim 2.   The nut inspection device according to claim 3, wherein the slit is formed obliquely with respect to the moving direction of the nut.

Images